|
Eupelycosauria
Eupelycosauria is a large clade of animals characterized by the unique shape of their skull, encompassing all mammals and their closest extinct relatives. They first appeared 308million years ago during the Early Pennsylvanian epoch, with the fossils of '' Echinerpeton'' and perhaps an even earlier genus, '' Protoclepsydrops'', representing just one of the many stages in the evolution of mammals,Kemp. T.S., 1982, ''Mammal-like Reptiles and the Origin of Mammals''. Academic Press, New York in contrast to their earlier amniote ancestors. Taxonomy Eupelycosaurs are synapsids, animals whose skull has a single opening behind the eye. They are distinguished from the Caseasaurian synapsids by having a long, narrow supratemporal bone (instead of one that is as wide as it is long) and a frontal bone with a wider connection to the upper margin of the orbit. Laurin, M. and Reisz, R. R., 1997Autapomorphies of the main clades of synapsids- Tree of Life Web Project The only living descen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kenomagnathus
''Kenomagnathus'' (meaning "gap jaw", in reference to the diastema in its upper tooth row) is a genus of synapsid belonging to the Sphenacodontia, which lived during the Pennsylvanian (geology), Pennsylvanian subperiod of the Carboniferous in what is now Garnett, Kansas, United States. It contains one species, ''Kenomagnathus scottae'', based on a specimen consisting of the maxilla and lacrimal bones of the skull, which was catalogued as ROM 43608 and originally classified as belonging to ''Haptodus garnettensis, "Haptodus" garnettensis''. Frederik Spindler named it as a new genus in 2020. Discovery and naming Norman Newell discovered a fossil locality near Garnett, Kansas, United States in 1931, belonging to the Rock Lake Member of the Stanton Formation. Around 1932, Henry Lane and Claude W. Hibbard, Claude Hibbard had collected a variety of animal and plant fossils from the locality. Among these were skeletons of ''Petrolacosaurus'', which were subsequently described in 1952 by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amniote
Amniotes are tetrapod vertebrate animals belonging to the clade Amniota, a large group that comprises the vast majority of living terrestrial animal, terrestrial and semiaquatic vertebrates. Amniotes evolution, evolved from amphibious Stem tetrapoda, stem tetrapod ancestors during the Carboniferous geologic period, period. Amniota is defined as the smallest crown clade containing humans, the Greek tortoise, and the Nile crocodile. Amniotes are distinguished from the other living tetrapod clade — the anamniote, non-amniote lissamphibians (frogs/toads, salamanders/newts and caecilians) — by: the development of three fetal membranes, extraembryonic membranes (amnion for embryonic protection, chorion for gas exchange, and allantois for metabolic waste disposal or storage); thicker and keratinized skin; rib, costal respiration (breathing by expanding/constricting the rib cage); the presence of adrenal cortex, adrenocortical and chromaffin cell, chromaffin tissues as adrenal g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Varanopidae
Varanopidae is an extinct family (biology), family of amniotes known from the Late Carboniferous to Middle Permian that resembled monitor lizards (with the name of the group deriving from the monitor lizard genus ''Varanus'') and may have filled a similar niche. Typically, they are considered to be relatively Basal (phylogenetics), basal Synapsida, synapsids (and thus more closely related to mammals than to reptiles), although some studies from the late 2010s recovered them being taxonomically closer to diapsid reptiles, recent studies from the early 2020s support their traditional placement as synapsids on the basis of high degree of bone labyrinth ossification, maxillary canal morphology and phylogenetic analyses. A varanopid from the late Middle Permian Pristerognathus Assemblage Zone, ''Pristerognathus'' Assemblage Zone (Capitanian) is the youngest known varanopid and the last member of the "pelycosaur" group of synapsids. Thus, Varanopidae vanishes from the fossil record at th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caseasauria
Caseasauria is one of the two main clades of early synapsids, the other being the Eupelycosauria. Caseasaurs are currently known only from the Late Carboniferous and the Permian, and include two superficially different families, the small insectivorous or carnivorous Eothyrididae, and the large, herbivory, herbivorous Caseidae. These two groups share a number of specialised features associated with the morphology of the snout and external nares, naris. The ancestor of caseasaurs can be traced back to an insect eating or an omnivorous reptile-like synapsid from the Pennsylvanian (geology), Pennsylvanian time of the Carboniferous, possibly resembling ''Archaeothyris'', the earliest known synapsid. The caseasaurs were abundant during the later part of the Early Permian, but by the Middle Permian caseasaur diversity declined because the group was outcompeted by the more successful therapsids. The last caseasaurs became extinct at the end of the Guadelupian (Middle Permian). Descript ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Edaphosauridae
Edaphosauridae is a family of mostly large (up to or more) Late Carboniferous to Early Permian synapsids. Edaphosaur fossils are so far known only from North America and Europe. Characteristics They were the earliest known herbivorous amniotes and, along with the Diadectidae, the earliest known herbivorous tetrapods. The head is small in relation to the bulky body, and there is a tall sail along the back, which may have functioned as a thermoregulatory device. Classification The interrelationships of Edaphosauridae was investigated in details by David M. Mazierski and Robert R. Reisz (2010). The cladogram A cladogram (from Greek language, Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an Phylogenetic tree, evolutionary tree because it does not s ... below is modified after their phylogenetic analysis. Below is a cladogram modified from the analysis of Benson (2012): ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synapsid
Synapsida is a diverse group of tetrapod vertebrates that includes all mammals and their extinct relatives. It is one of the two major clades of the group Amniota, the other being the more diverse group Sauropsida (which includes all extant reptiles and therefore, birds). Unlike other amniotes, synapsids have a single temporal fenestra, an opening low in the skull roof behind each eye socket, leaving a zygomatic arch, bony arch beneath each; this accounts for the name "synapsid". The distinctive temporal fenestra developed about 318 million years ago during the Late Carboniferous period, when synapsids and sauropsids diverged, but was subsequently merged with the orbit in early mammals. The basal (phylogenetics), basal amniotes (reptiliomorphs) from which synapsids evolved were historically simply called "reptiles". Therefore, stem group synapsids were then described as mammal-like reptiles in classical systematics, and non-therapsid synapsids were also referred to as pelyco ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ophiacodontidae
Ophiacodontidae is an extinct family of early synapsids from the Carboniferous and Permian. '' Archaeothyris'', and '' Clepsydrops'' were among the earliest ophiacodontids, appearing in the Late Carboniferous. Ophiacodontids are among the most basal synapsids, an offshoot of the lineage which includes therapsids and their descendants, the mammals. The group became extinct by the Kungurian or the Roadian, replaced by anomodonts, theriodonts, and the diapsid reptiles. Characteristics The lifestyle of ophiacodonts has long been controversial. Some studies suggested that they were semi-aquatic, and some even suggested a fairly aquatic lifestyle, but a recent study based on a quantitative inference model suggested that both '' Clepsydrops'' and '' Ophiacodon'' were terrestrial. Vertebral morphometric data also support, though ambiguously, a rather terrestrial lifestyle for '' Ophiacodon'', which could reach a length of . '' Archaeothyris'' may also have been terrestrial, but no ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Milosaurus
''Milosaurus'' is an extinct genus of non-mammalian synapsids native to Illinois that was alive during the latest Carboniferous and earliest Permian. It was named in 1970 on the basis of FMNH 701, a partial skeleton, as well as referred material.R. DeMar. 1970. A primitive pelycosaur from the Pennsylvanian of Illinois. ''Journal of Paleontology'' 44(1):154-163 Discovery The holotype A holotype (Latin: ''holotypus'') is a single physical example (or illustration) of an organism used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of s ... of ''Milosaurus'' was found in the Falmouth locality in Jasper County, Illinois. At the time, the discovery was only the second sphenacodont found in Illinois, the first being '' Macromerion''. Since then the assignment of ''Milosaurus'' to Sphenacodontia has been refuted. The name ''Milosaurus'' ''mccordi'' refers to Milo Flynn and Chester Mc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sphenacodontia
Sphenacodontia is a stem-based taxon, stem-based clade of derived synapsids. It was defined by Amson and Laurin (2011) as "the largest clade that includes ''Haptodus baylei'', ''Haptodus garnettensis'' and ''Sphenacodon ferox'', but not ''Edaphosaurus pogonias''". They first appear during the Late Pennsylvanian (Upper Carboniferous) epoch. From the end of the Carboniferous to the end of the Permian, most of them remained large, with only some secondarily becoming small in size. Basal (phylogenetics), Basal Sphenacodontia constitute a Transitional fossils, transitional evolutionary series from early pelycosaurs to ancestral therapsids (which in turn were the ancestors of cynodont, more advanced forms and finally the mammals). One might say that the sphenacodontians are proto-therapsids (even though there is almost a 30-million-years gap between the separation of the ancestors of therapsids from other sphenacodontians and the first appearance of therapsids in the fossil record). Ch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mammal
A mammal () is a vertebrate animal of the Class (biology), class Mammalia (). Mammals are characterised by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three Evolution of mammalian auditory ossicles, middle ear bones. These characteristics distinguish them from reptiles and birds, from which their ancestors Genetic divergence, diverged in the Carboniferous Period over 300 million years ago. Around 6,640 Neontology#Extant taxon, extant species of mammals have been described and divided into 27 Order (biology), orders. The study of mammals is called mammalogy. The largest orders of mammals, by number of species, are the rodents, bats, and eulipotyphlans (including hedgehogs, Mole (animal), moles and shrews). The next three are the primates (including humans, monkeys and lemurs), the Artiodactyl, even-toed ungulates (including pigs, camels, and whales), and the Carnivora (including Felidae, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Edaphosaurus
''Edaphosaurus'' (, meaning "pavement lizard" for dense clusters of its teeth) is a genus of extinct edaphosaurid synapsids that lived in what is now North America and Europe around 303.4 to 272.5 million years ago, during the Late Carboniferous to Early Permian. The American paleontologist Edward Drinker Cope first described ''Edaphosaurus'' in 1882, naming it for the "dental pavement" on both the upper and lower jaws, from the Greek ' ("ground"; also "pavement") and (') ("lizard"). ''Edaphosaurus'' is important as one of the earliest-known, large, plant-eating ( herbivorous), amniote tetrapods (four-legged land-living vertebrates). In addition to the large tooth plates in its jaws, the most characteristic feature of ''Edaphosaurus'' is a sail on its back. A number of other synapsids from the same time period also have tall dorsal sails, most famously the large apex predator ''Dimetrodon''. However, the sail on ''Edaphosaurus'' is different in shape and morphology. The firs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Michel Laurin
Michel Laurin is a Canadian-born French vertebrate paleontologist whose specialities include the emergence of a land-based lifestyle among vertebrates, the evolution of body size and the origin and phylogeny of lissamphibians. He has also made important contributions to the literature on phylogenetic nomenclature. As an undergraduate, he worked in the laboratory of Robert L. Carroll and earned his Ph.D. at the University of Toronto under the direction of Robert R. Reisz; his thesis concerned the osteology of Seymouriamorpha, seymouriamorphs. His 1991 review of diapsid phylogeny provided the broadest review of the subject up to that date. In 1995, Laurin and Reisz coauthored a widely cited article providing evidence that the synapsids are the sister group of all other amniotes. He later worked on untangling the phylogeny of the Stegocephalia, a group with a notoriously difficult phylogeny. He later moved to France; since 1998, he has been a CNRS researcher at the Muséum National d'H ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
